The present invention relates to a security element for manufacturing value documents, such as banknotes, checks or the like, that comprises a top on which is developed a microrelief structure that has at least two sub-regions that each comprise a plurality of groove- or rib-shaped structural elements that lie adjacent to one another and extend along a longitudinal direction, and are reflecting or backscattering, the longitudinal directions of the sub-regions being different.
The present invention further relates to a value document having such a security element.
The present invention also relates to a manufacturing method for a security element for value documents, such as banknotes, checks or the like, a substrate being provided that comprises a top, and on the top, a microrelief structure being developed that has at least two sub-regions that each comprise a plurality of groove- or rib-shaped structural elements that lie adjacent to one another and extend along a longitudinal direction, and are reflecting or backscattering, the longitudinal directions of the sub-regions being different.
In the prior art, security elements are known that provide optically variable areal patterns. Such optically variable areal patterns can produce running effects or three-dimensional-appearing depictions. Here, the effects are achieved through diffraction gratings (e.g. in the form of holograms), micromirrors or a combination of microlenses and microimages.
WO 2012/069163 A1 discloses a security element that consists of retroreflectors that are provided with a color-variable coating. Through an interplay of single and multiple reflections in the retroreflectors having the angle-dependent color of the coating (especially thin-film coating having an angle-dependent “colorshift”), special color effects are produced. As a special case, groove structures are disclosed as retroreflectors that realize pump and running effects. The cited pump or running effects refer to moving color changes. It is further mentioned that, with such groove structures, it is possible to realize also three-dimensional-appearing depictions by varying the groove direction.
WO 2011/079347 A1 discloses how to produce three-dimensional effects with groove- or rib-like structures. For this, either the structures can follow the height contour of a bulged area or, with the structures, different views of an object for the left and right eye of a viewer can be provided.
WO 2012/048847 A1 discloses a security element that provides depictions that are composed of points or lines that seemingly float in front of or behind the plane of the security element. Said points or lines are referred to as light spots and are given by focus points and lines of concave or convex mirrors. To achieve this effect, a viewer must see, in each case, the light spots of a lens structure with both eyes. In a cylindrical lens structure, the appropriate focal lines are perceived at different locations with both eyes. The height or depth at which the light spot floats in front of or behind the plane of the security element depends on the focal length. The required structures are relatively complex to manufacture.